2002
Report # 10
4 p.m. CST, Wednesday, Feb. 20, 2002
Expedition Four Crew
Expedition 4 astronauts Carl Walz and Dan Bursch completed a successful 5-hour,
47-minute spacewalk Wednesday, testing equipment and procedures for the Airlock
Quest and performing other tasks to prepare for Space Shuttle Atlantisí STS-110
mission to the International Space Station in April. The spacewalk, which began at 5:38
a.m. CST and ended at 11:25 a.m., notched some firsts.
It was the first spacewalk from Quest without the presence of a space shuttle at the
station, earning it the designation of U.S. EVA 1. It also marked the first U.S. use of an
Intravehicular (IV) officer, Astronaut Joe Tanner, working from Houstonís Mission
Control Center instead of from onboard the spacecraft, as has been the case up to this
point. Also, new procedures were used to expedite airlock depressurization at the start
of the spacewalk.
STS-110 will bring the S0 Truss to the station, the first segment of what will be the
stationís backbone. Four spacewalks will be conducted during that flight, all from the
airlock and all using an oxygen/exercise protocol to purge nitrogen from the
spacewalkersí bloodstreams. Walz and Bursch used that protocol today.
During the spacewalk today, Walz and Bursch deployed two electrical cables from their
stowage area on the U.S. Laboratory Destiny and connected them to a cable tray near the
base of the Z1 Truss. Plans to disconnect and restow the cables were put on hold while
engineers evaluated unexpected readings from current conversion units in the circuit
the cables completed. Walz removed four thermal blankets from the Z1 Truss and
stowed them inside the truss, while Bursch retrieved tools to be used on STS-110
spacewalks and brought them to the airlock. The two also secured looser-than-expected
latches on two oxygen tanks and two nitrogen tanks, on the airlock.
Walz and Bursch removed adaptors on which a Russian cargo crane had been mounted and
attached one of them to the Zarya moduleís exterior. They brought the other, U.S.-made,
adaptor into the airlock. They also inspected cable connectors outside the station and
photographed the MISSE (Materials International Space Station Experiment). Some of
the materials samples being exposed to the harsh conditions of space apparently were
peeling back off their mountings.
Scientists used the spacewalk to gather additional data for an experiment looking at the
effects of spacewalks and long-term exposure to microgravity on lung function. Also,
Walz and Bursch will wear radiation sensors for the EVARM experiment, a study of
radiation doses experienced by spacewalking astronauts.
Walz and Bursch each had made one previous spacewalk from the station last month, and
Walz also made a spacewalk on STS-51 in September 1993. During todayís spacewalk,
Expedition 4 Commander Yury Onufrienko operated cameras on the stationís Canadian
provided robotic arm to document activities.
A planned upgrade of the stationís software is scheduled for late this week to prepare
station computers for arrival of the S0 Truss and other equipment to be delivered on
subsequent flights.
Information on the crew's activities aboard the space station, future launch dates, as
well as station sighting opportunities from anywhere on the Earth, is available on the
internet at:
http://spaceflight.nasa.gov
Details on station science operations can be found on an internet site administered by the
Payload Operations Center at NASA's Marshall Space Flight Center in Huntsville, Ala., at:
http://www.scipoc.msfc.nasa.gov
The next ISS status report will be issued Feb. 22, or sooner, if developments warrant.
END